Straight chuck

ABSTRACT

This invention relates to a straight chuck of collet type setting in vertical machine tools to use. Revolving a collar along the direction of removal of it, the collet retained within the body portion of the straight chuck and fastened or clamped the external periphery can be loosed and a tool may be removed. During the revolution of the collar and the loosening of the collet, an upper inclined surface of the collet only in the beginning is disengaged from an opposite and corresponding inclined surface of the body of the straight chuck, without loosening of a shank instantly and throughly, then the collet is prevent from dropping, finally a cramp ring is disengaged from the lower inclined surface so as to loose the tool. From beginning to end, the collet of the straight chuck in accordance with the invention has a sufficient and constant cramp force to prevent the tool from loosing and dropping.

Kanebarko et a1.

[ STRAEGHT CHUCK [75] Inventors: Hiromu Kanebako; Kazutoshi Wada, bothof Kimatsu-gun, Chiba, Japan [73] Assignee: Kuroda Seiko Company, Ltd.,Otaku, Tokyo, Japan [22] Filed: May 21, 1971 [21] Appl. No: 145,854

[30] Foreign Application Priority Data June 4, 1970 Japan ..45/54442[52] U.S. Cl ..279/48, 279/56 [51] Int. Cl. ..B23b 31/20 [58] Field ofSearch ..279/48, 49, 56, 36

[56] References Cited I UNITED STATES PATENTS 2,272,185 2/1942Chittenden ..279/49 1,880,521 10/1932 Stowell ..279/36 X 2,573,32510/1951 Fowlie ..279/56 3,734,513 May 22, 1973 Primary ExaminerAndrew R,Juhasz Assistant Examiner-Z. R. Bilinsky Att0mey-Polachek & Saulsbury[57] ABSTRACT This invention relates to a straight chuck of collet typesetting in vertical machine tools to use. Revolving a collar along thedirection of removal of it, the collet retained within the body portionof the straight chuck and fastened or clamped the external periphery canbe loosed and a tool may be removed.

and dropping.

2 Claims, 6 Drawing Figures PATENTE #42122 [975 H romu KanebaKo mvmonsKazutoshi Wada ATTORNEYS STRAIGHT CHUCK DETAILED DESCRIPTION OFINVENTION This invention relates to a straight chuck having colletsetted in and used by a vertical type machine tool, and moreparticularly to a straight chuck provided with a drop preventingmechanism of tools held in the chuck.

Up to this time, straight chucks provided with collet for tools havingstraight shanks are troublesome and difficult to receive the tools in,and thereby the tools likely to happen dropped from the chuck accidentlyand carelessly. In particular, when drills or cutters are used and theyare dropped from the chuck, edges of the drills are broken and snappedfrequently, or the work on the table face or table face itself of themachine tool is damaged.

In general, the prevent invention contemplates the provision of astraight chuck provided with a collet, characterized by the innerperiphery of the collet received within the main chuck body cramps andholds a straight shank of any tool, and in spite of the collet isloosed, the collet of the straight chuck has a sufficient and constantcramp force to prevent the tool from loosing and dropping.

A principal object of the present invention is to provide a straightchuck having a collet in which the collet is fitted within the chuckbody, and the cramping and loosing are regulated microscopically byhorizontal smooth revolution of a collar provided on the outer, lowerportion of the chuck body.

Another object of the present invention is to provide a straight chuckprovided with a collet, in which the collet is fitted within the chuckbody, and an upper half face and a lower half outer face of a collet arecramped or loosened alternately, a straight shank portion of a toolmounted in the collet is retained firmly when the collet is cramped, andthe straight shank portion is held also with sufficient and constantforce to prevent the tool from loosing and dropping even when the colletis loosed.

A further object of the invention is to provide a straight chuck havinga collet, wherein the collet is fitted within the chuck body, a stoppingfrange is arranged around the top and peripheral portion of the collet,and when a shank portion of a tool is inserted within the bore of thecollet, said stopping frange of the collet is supported constantly by areceiving inclined surface arranged on the inner peripheral surface ofthe chuck body, thus the stopping frange prevent the collet fromdropping.

In order that the present invention may be more easily understood, andonly by way of example, a sheet of drawings is attached in which showingof the straight chuck according to the present invention is being made.

FIG. 1 shows a side sectional view of the straight chuck according tothe present invention.

FIG. 2 shows a sectional view of a part taken along the line 2 2 shownin FIG. 1.

FIG. 3 FIG. 5 are all sectional view of showing the sequential steps ofloosing the collet mounted within the straight chuck.

FIG. 6 shows a perspective view of the collet.

On the hollow upper portion of the chuck body 11 as shown in FIG. 1,which indicates the whole of the chuck body, a thread 12 for connectingthe chuck body with a operating shaft is provided, and a hollow portion13 connected to the thread portion and an inclined hollow portion 14extended horizontally, as shown in FIG. 3, are also provided.

A manual handling frange 15 is provided on the appropriate portion ofthe peripheral outer surface of the chuck body 11, and a thread 16 isprovided on the outer periphery of the lower edge of the chuck body soas to threadly engage with the thread of the collar 17.

Within the inclined hollow portion 14, a collet 18 having an upper halfinclined surface and a lower half inclined surface is fitted, and then ashank portion 33 of any tool is inserted upwardly into the hollowportion 19 of the collet 18 and is retained there.

The collet 18 as shown in FIG. 6 have a hollow cylinderical shape, whichhas upper and lower inclined surfaces 20, 21 respectively of circulartruncated cone. On the circular wall of the collet 18, slots 22, 23 arearranged one after the other, extending longitudinally from one of theupper and lower openings of the hollow portion 19 receiving a shankportion 33 of any tool to the neighbor portion of the other.

Owing to the slots 22, 23, a little pressure providing on the outersurface of the collet 18 causes shrinkage of the inner surface of saidcollet. Extruding edge 24 arranged around the periphery of top portionof said collet 18 is engaged on the stopping and corresponding surface25 provided within the chuck body above the inclined hollow portion 14thereof, thereby the collet 18 is supported in place.

The inclined surface 27 engaging with the inclined surface 21 arrangedon the lower half surface of said collet 18 is provided on the innersurface of a ring 26 engaged with the inner periphery of said collar,and balls 28 are engaged in a hollow opening composed of the grooves ofsemicircular section provided on the ring 26 and the collar 17respectively. The balls 28 are as shown clearly in FIG. 2 arranged asring-shape. The balls 28 are introduced into the hollow opening throughthe introducing passage 29 arranged in the collar 17, and the passage isclosed by a small screw 30.

Knurled portion 31 or depressed portion 32 for driving tool may bearranged appropriatly on the surface of said collar 17. After a shank 33of any tool is inserted upwardly and completely into the collet 18 ofthis invention, the collar 17 is made revolution along a fixed directionhorizontally and it is made upward movement along the thread 16 on thelower portion of the chuck body 11. Accordingly, the inner face of thering 26 which is engaged with the collar 17 through the balls 28 pushesthe lower half inclined surface 21. Furthermore, the collar 17 isremoved, the upper half inclined surface 20 of the collet 18 pushes thehollow inclined portion 14 of the chuck body 11 thereby the circularwall of collet 18 is shrinked generally and the shank portion 33 of thetool is cramped and grasped firmly by the inner surface of the collet.

When the collar 17 is revolved in opposite direction, the ring 26 isdowned smoothly and it is disengaged from the lower half surface ofcollet 18, and the inner surface of the circular wall the collet 18 isdisengaged from the shank portion 33 of the tool, thus the tool may bepulled out.

If the angle of inclination of the upper half surface 20 of the collet 18 is made more steep than that of the lower half surface 21, the upperhalf surface 20 is, during revolution of the collar 17, disengaged fromthe inclined face 14 of chuck body 11 first, then later the lower halfsurface 21 is disengaged from the inclined surface 27 of the ring 26 andthe collet 18 cramping a shank portion 33 of any tool is loosed to beable to pull out the tool.

When the upper half inclined surface 20 of the collet 18 is separatedfrom the inclined face of the chuck body 11, the extruding edge 24arranged around the periphery of top portion of said collet 18 is movedoutwardly and engaged firmly with the stopping surface 25, thus even ifthe collet 18 is sufficiently loosed for removal of the tool shaft 33,it is held securely within the chuck body.

FIG. 3 FIG. show a sequential steps of a loosing the shank portion 33 ofa tool.

While one form of the invention has been shown for purposes ofillustration, it is to be clearly understood that various changes in thedetails of construction and arrangement of parts may be made withoutdeporting from the spirit and scope of the invention as set forth in theappended claims.

We claim:

1. A straight chuck comprising, in combination: a chuck body providingupper and lower ends, defining a concentric hollow channel openingconcentrically at the lower end and receivable of an operating toolshaft, and having a lower annularly male-threaded portion, said chuckbody hollow channel being formed as chuck body inner upper and lowerwalled truncated cones; a constricting annular collar defining a channelnarrowed at a lower end thereof and having inner-channel female-threadsmateable with and mounted on the male-threaded portion so as to revolvethe restricting collar horizontally in a plane vertical to said hollowchannel; a collet having outer walls shaped as three axially alignedcones, the upper two truncated cones fixedly integrally connected at therespective cones narrowed truncated ends, in which walls defining theupper collet truncated-cone of the collet are more inwardly inclinedthan walls of the collet middle truncated cone, the collet lower conebeing connected at the broad end of the middle second truncated cone,and said collet being mounted in the hollow channel of the chuck bodywith said collet upper truncated cone receivable within thecorresponding chuck upper truncated cone; a rotatable ring having innerannular walls defining a lower truncated cone axially aligned with saidhollow channel and with said collet lower truncated cone, and withnarrowed ends of the collet lower truncated cone and the ring truncatedcone in juxtaposition with one-another and spaced from one-another whensaid collar is revolved to a state for removal or mounting of a toolshaft, the upper truncated cone of the chuck body and the upper colletcone each being inwardly inclined more than inwardly inclined truncatedcone walls of the lower collet cone and of the ring cone; and the colletlower truncated cone being receivable within the corresponding ringtruncated cone with their corresponding narrowed cone ends injuxtaposition, the broadened upper end of the ring cone being injuxtaposition to the broadened upper end of the lower chuck cone; saidcollet having slots each having one open end, extending longitudinallyfrom one of the upper and lower openings of the annular collet walls andextending in axial directions between opposite ends of the collet, withslots alternating in the open-slot end as between alternately oppositeends of the collet; and said upper truncated cones respectively of thechuck and the collet being coordinately inter-actable to exert inwardholding-pressure on a tool shank whenever a force moves rotatably saidcollar in an axially distal direction whereby the upper chuck and colletcones walls come into contact with one-another, to prevent the tool fromdropping from the chuck preparetory to removal of the tool shaft fromthe chuck.

2. A straigh chuck as claimed in claim 1, wherein balls are arranged ina circle and engaged in a hollow opening composed of grooves ofsemicircular section provided on the ring and the collar respectively.

1. A straight chuck comprising, in combination: a chuck body providingupper and lower ends, defining a concentric hollow channel openingconcentrically at the lower end and receivable of an operating toolshaft, and having a lower annularly malethreaded portion, said chuckbody hollow channel being formed as chuck body inner upper and lowerwalled truncated cones; a constricting annular collar defining a channelnarrowed at a lower end thereof and having inner-channel female-threadsmateable with and mounted on the male-threaded portion so as to revolvethe restricting collar horizontally in a plane vertical to said hollowchannel; a collet having outer walls shaped as three axially alignedcones, the upper two truncated cones fixedly integrally connected at therespective cones narrowed truncated ends, in which walls defining theupper collet truncated-cone of the collet are more inwardly inclinedthan walls of the collet middle truncated cone, the collet lower conebeing connected at the broad end of the middle second truncated cone,and said collet being mounted in the hollow channel of the chuck bodywith said collet upper truncated cone receivable within thecorresponding chuck upper truncated cone; a rotatable ring having innerannular walls defining a lower truncated cone axially aligned with saidhollow channel and with said collet lower truncated cone, and withnarrowed ends of the collet lower truncated cone and the ring truncatedcone in juxtaposition with one-another and spaced from one-another whensaid collar is revolved to a state for removal or mounting of a toolshaft, the upper truncated cone of the chuck body and the upper colletcone each being inwardly inclined more than inwardly inclined truncatedcone walls of the lower collet cone and of the ring cone; and the colletlower truncated cone being receivable within the corresponding ringtruncated cone with their corresponding narrowed cone ends injuxtaposition, the broadened upper end of the ring cone being injuxtaposition to the broadened upper end of the lower chuck cone; saidcollet having slots each having one open end, extending longitudinallyfrom one of the upper and lower openings of the annular collet walls andextending in axial directions between opposite ends of the collet, withslots alternating in the open-slot end as between alternately oppositeends of the collet; and said upper truncated cones respectively of thechuck and the collet being coordinately inter-actable to exert inwardholding-pressure on a tool shank whenever a force moves rotatably saidcollar in an axially distal direction whereby the upper chuck and colletcones'' walls come into contact with one-another, to prevent the toolfrom dropping from the chuck preparetory to removal of the tool shaftfrom the chuck.
 2. A stRaigh chuck as claimed in claim 1, wherein ballsare arranged in a circle and engaged in a hollow opening composed ofgrooves of semicircular section provided on the ring and the collarrespectively.